CVE-2012-0920 Use after free in n/a

What is CVE-2012-0920?

CVE-2012-0920 is a high-severity use after free vulnerability in Debian Debian Linux, published on 5 Jun 2012. Any signed-in user can exploit it over the network, with no action from the victim.

Official description

Use-after-free vulnerability in Dropbear SSH Server 0.52 through 2012.54, when command restriction and public key authentication are enabled, allows remote authenticated users to execute arbitrary code and bypass command restrictions via multiple crafted command requests, related to "channels concurrency."

Weakness: CWE-399

Which versions are affected by CVE-2012-0920?

It affects 2 products.

Products include Debian Debian Linux, Dropbear Ssh Project Dropbear Ssh.

How do I fix CVE-2012-0920?

Apply the vendor's patch.

Upgrade to the fixed version. These bugs are found with fuzzing and sanitisers and avoided by memory-safe languages. More about Use after free.

Is CVE-2012-0920 being exploited?

There is no known exploitation of CVE-2012-0920 in the wild and no public exploit code.

Other vulnerabilities in Debian Debian Linux

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• CVE-2025-49113 RoundCube Webmail Deserialization of Untrusted Data Exploited Critical 9.9
• CVE-2026-24061 GNU InetUtils Argument Injection Exploited Critical 9.8
• CVE-2025-39682 Linux Kernel Improper Check for Unusual or Exceptional Conditions Exploited Critical 9.8
• CVE-2024-9680 Mozilla Firefox Use-After-Free Exploited Critical 9.8

All Debian Debian Linux vulnerabilities

Sources

• CVE record
• NVD
• OSV
• GitHub advisory
• How this page is made

Also known as DEBIAN-CVE-2012-0920, DSA-2456-1, GHSA-hw56-hwpj-4432.